TransformationHistoryImages.java

package org.bundlemaker.core.ui.view.transformationhistory.internal;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.swt.graphics.Image;

/**
 * @author Nils Hartmann (nils@nilshartmann.net)
 * 
 */
public enum TransformationHistoryImages {

  /**
   * the "reset history" icon
   */
  RESET_ICON("icons/reset.png"),

  /** Pin selection */
  PIN_SELECTION("icons/pin-selection.png"),

  /** Pin Selection */
  PIN_SELECTION_DISABLED("icons/pin-selection-add.png"),

  /** Undo last Transformation */
  UNDO_TRANSFORMATION("icons/undo-transformation.png")

  ;

  /**
   * The bundle-relative path to the icon
   */
  private final String path;

  private TransformationHistoryImages(final String path) {
    this.path = path;
  }

  /**
   * Returns an image. Clients do not need to dispose the image, it will be disposed automatically.
   * 
   * @return an {@link Image}
   */
  public Image getImage() {
    final ImageRegistry imageRegistry = Activator.getDefault().getImageRegistry();
    Image image = imageRegistry.get(this.path);
    if (image == null) {
      addImageDescriptor();
      image = imageRegistry.get(this.path);
    }

    return image;
  }

  /**
   * Returns an image descriptor.
   * 
   * @return an {@link ImageDescriptor}
   */
  public ImageDescriptor getImageDescriptor() {
    final ImageRegistry imageRegistry = Activator.getDefault().getImageRegistry();
    ImageDescriptor imageDescriptor = imageRegistry.getDescriptor(this.path);
    if (imageDescriptor == null) {
      addImageDescriptor();
      imageDescriptor = imageRegistry.getDescriptor(this.path);
    }

    return imageDescriptor;
  }

  private void addImageDescriptor() {
    final Activator plugin = Activator.getDefault();
    final ImageDescriptor id = ImageDescriptor.createFromURL(plugin.getBundle().getEntry(this.path));
    plugin.getImageRegistry().put(this.path, id);
  }

}